The goal of this contract is to collect, maintain and distribute sera from individuals with cancer, benign diseases or no disease in order to evaluate the clinical usefulness of serum assays of putative tumor markers. The original NCI Immunodiagnostic serum bank was established in 1972 to provide a reservoir of sera from the most common types of cancer, benign diseases and health controls. In 1975 the Serum Bank for the Breast Cancer Task Force was added to the workscope to provide serial specimens of sera from patients with both malignant and benign breast tumors. The present contract combines the 2 banks into a single Diagnosis Serum Bank. The sera are stored at -0 degrees C with continuous monitoring to assure maintenance of this temperature and protection of sample quality. A computerized clinical data and inventory system is in operation. The Project Officer makes sera available in response to requests from investigators for evaluation of promising biochemical and immunodiagnostic tests. The sera are provided in coded panels designed to allow determination of the sensitivity and specificity of the potential markers and their comparative values with other tumor markers.